Except for trim, I use eggshell on everything. Well, I use flat on ceilings only. Anyway, eggshell will certainly look duller, but it won't accentuate every tiny defect in he wall either. You should be able to paint right over the satin as long as there are two good coats everywhere. I've heard some bozos say you shouldn't do that or it'll peel, but they obviously falsely assume that satin = oil based and eggshell = latex. Wrong! A latex eggshell can be applied right over a latex satin. If you're not fully convinced, then put a coat of primer over everything and then apply your latex.

If you are ready to switch finishes and repaint, go with Aura Matte for walls. With Aura, there is no need to go with higher sheen to get durability. Since it does have some angular sheen, I would suggest a flat finish for the ceilings.

I had to decide fast so I talked to the people at Benjamin Moore. They were wishy washy about switching finishes midstream and I already had the satin paint so I went ahead and did one coat with that and then did the second coat in matte. It looks orders of magnitude better. There are a couple of places near the trim where a little sheen shows through but that should come up with touch up. I haven't done it yet but they say touch ups won;t show with the Aura.